Ultrasonic degreasing apparatus



Sept. 26, 1961 L. E. PLASSMEYER ULTRASONIC DEGREASING APPARATUS Filed Feb. 27, 1959 2 Sheets-Sheet 1 Z 00/: [da/am/ P/aufleyer INVENTOR ATTORNEY Sept. 26, 1961 L. E. PLASSMEYER 3,001,532

ULTRASONIC DEGREASING APPARATUS Filed Feb. 27, 1959 2 Sheets-Sheet 2 INVENTOR ATTORNEY 3,001,532 ULTRASONIC DEGREASIN G APPARATUS Louis Edward Plassmeyer, Evanston, 111., assignor to Phillips Manufacturing Company, Chicago, 111., a corporation of Illinois Filed Feb. 27, 1959, Ser. No. 796,002

13 Claims. (Cl. 134-408) nited States Patent flected in and through said solvent in predetermined directions towards the various surfaces of the work pieces submerged in said solvent by positioned cushioned reflecting means, said directions being determined and fixed by the geometry and position of the said reflecting means in said solvent. The ultrasonic degreasing apparatus also includes means for controlling the temperature of the solvent and means for intermittently filtering the solvent, each of said means being capable of operation and being operable separately from and exclusively of each other whereby the solvent temperature can be and is controlled independently of the filtering of the solvent. The temperature controlling means is a coolant coil, preferably a multiple-pass coolant coil, which is so positioned in the solvent that the ultrasonic vibrations generated in the solvent are reflected by said coolant coil.

With the advent of barium titanate transducers which result in the more eflicient and more economical generation of ultrasonic vibrations in and through a liquid body such as the solvent used in the cleaning and degreasing of metal parts or workpieces, the problem of Obtaining maximum efliciency with such transducers presented itself. Cleaning and degreasing solvents which are commonly used in cleaning and degreasing apparatus are liquid chlorinated hydrocarbons such as trichlorethylene and perchlorethylene, the latter also being known as tetrachlorethylene. The most commonly used solvent is trichlorethylene. In order to obtain the maximum efficiency in an ultrasonic degreasing apparatus wherein the ultrasonic vibration generating means comprises a barium titanate transducer or a plurality of barium titanate transducers I have found that the temperature of the solvent in which the transducer, or transducers, is, or are, submerged and through and in which the ultrasonic vibrations are generated must be maintained within a certain temperature range, this temperature range being approximately between 150 F. and 160 F. for trichlorethylene as a solvent, in order to obtain maximum efliciency and maximum generation of ultrasonic vibrations. Also, it is necessary to filter the solvent to separate from it the foreign matter accumulated in the solvent during the cleaning operation. Heretofore, in ultrasonic degreasing apparatus, the filtering means and the temperature control means, usually in the form of a heat exchanger, utilized have been in combination, viz. in a single flow circuit, and there has sometimes been included therein a thermostatically operated valve in said circuit, whereby both the filtering and cooling operations are carried out simultaneously depending upon the temperature of the solvent at any certain time during the cleaning operation. Also, in some heretofore known apparatus, the filtering means is used both as a cooling means and filtering means, and additional cooling of the solvent is accomplished by solvent spraying means. In such hereto- 3,001,532 Patented Sept. 26, 1961 fore known apparatus the filtering and cooling requires the circulation of the solvent from the ultrasonic chamber through a piping system outside of the chamber, said piping system having therein the filter, or the filter and the heat exchanger or coil, positioned outside of the chamber, and the solvent is necessarily repeatedly aerated. In such apparatus, especially that type which has only the filter used both as a filter and a heat exchanger, almost continuous circulation is required to keep the temperature of the solvent within the required limits, viz. F. F., thus causing repeated aeration of the solvent, which results in the decrease in efficiency of the system due to the power loss caused by the resistance of the air in the solvent to the ultrasonic vibrations generated. Further, there is a decrease in the cooling eificiency of the heat exchanger and/or the filter by reason ocf the same being outside of the chamber.

The ultrasonic degreasing apparatus of my invention includes a cooling means and a filtering means, each of which can be operated, and is operated, separately from and exclusively of each other. By so utilizing two separate flow circuits, one for controlling the temperature of the solvent and the other for filtering the solvent, I am able to keep the solvent temperature within the required temperature range, viz. 150 F.160 F., without circulating the solvent but rather by passing coolant through the coil, preferably a multiple-pass coolant coil, thereby eliminating substantial aeration of the solvent and thereby eliminating substantial power losses with respect to the operation of the ultrasonic vibration means, and

. I am able to keep the solvent free from collected dirt and other foreign matter accumulated during the cleaning operation by filtering the solvent intermittently by circulation through the filter circuit only at minimum requirements, thereby obviating substantial aeration of the solvent caused by continuous filtering. In my operation, the filtering circuit is not required for controlling the temperature of the solvent.

An object of my invention is to provide an ultrasonic degreasing apparatus comprising cushioned means for reflecting ultrasonic vibrations through and in the cleaning solvent whereby the solvent impinges against a plurality of surface portions of the work piece submerged in the solvent and whereby a maximum of ultrasonic vibrations generated through and in the solvent is reflected by said reflecting means.

Another object of my invention is to provide an ultfasonic degreasing apparatus comprising cushioned means for reflecting ultrasonic vibrations through and in the cleaning solvent and coolant coil means for controlling the solvent temperature, said coil means being submerged in the solvent whereby the solvent impinges against a plurality of surface portions of the work piece submerged in the solvent and whereby a maximum of ultrasonic vibrations is reflected by said reflecting means and said coil means.

Another object of my invention is to provide an ultrasonic degreasing apparatus comprising coolant coil means submerged in the cleaning solvent for controlling the solvent temperature within required temperature limits and means for intermittently filtering said solvent, said coolant coil means and said filtering means being operable separately from and exclusively of each other, whereby the solvent temperature can be properly controlled independently of the filtering of the solvent thereby to prevent any substantial aeration of the solvent.

Other objects and features of my invention will become readily appearent from the following detailed description which is not limiting but only descriptive of my invention.

FIGURE 1 is a cutaway view in perspective of my utrasonic degreasing apparatus.

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FIGURE 2 is a plan view of my ultrasonic degreasing apparatus.

FIGURE 3 is a cutaway view in perspective of a portion of my ultrasonic degreasing apparatus specifically showing the baffle means for reflecting the ultrasonic vibrations through the solvent.

, More specifically, the ultrasonic degreasing apparatus of my invention includes the sheet metal compartmented tank 2 which is divided by the double wall divider 4 into boiling chamber 6 and ultrasonic chamber 8 and has vapor portion 10 above both chambers. In both chambers ,6 and 8 is cleaning solvent filling ultrasonic chamber 8 to level A and overflowing to boiling chamber 6 to level B. Preferably mounted on wall 12 of ultrasonic chamber 8 are the transducers 14, 16, and 18, each in its respective housing 14a, 16a, and 18a, each being submerged in the solvent and connected through their respective electrical conductors (not shown) to an electrical oscillator (not shown). Positioned in the ultrasonic chamber 8 is multiple-pass coolant coil 20 which is vertically positioned therein and submerged in the solvent, said coil 20 passing through Wall 22 at openings 24 and 26. The coil 28 is provided with manually controlled valve 28 to control the water flow therethrough, as required. Attached to wall 30 of double divider wall 4 and sidewalls and 42 of ultrasonic chamber 8 are baffles 32 and 34 forming the air spaces 36 and 38, as clearly shown in the appended drawings. Top plates 44 and 46 are affixed to sidewalls 40 and 42 and to baffles 32 and 34 and to Wall 30 as, for example, by welding to cover air spaces 36 and 38, thereby allowing solvent to flow from ultrasonic chamber 8 over plates 44 and 46 and of double divider wall 4 into boiling chamber 6. Positioned at the .bottom of boiling chamber 6 is heating coil 48 over which is positioned and supported perforated tray 50 upon which the work piece or work pieces to be cleaned and degreased are positioned against all of the surface portions of the work pieces. Should the temperature of the solvent rise above the temperature range 150 -F.16 F., coolant is passed through the coolant coil 20 until the temperature decreases. Should there accumulate an excess of foreign matter, the solvent is filtered through filter means 70, as required. The work piece is then removed from chamber 8 into the vapor space 10 and subjected to the vapors until solvent stops dripping therefrom and said work piece dries.

It is clearly evident from the foregoing description that the solvent is caused to reach all portions of all surfaces of a multi-surfaced work piece by reason of ultrasonic vibrations generated in and through the entire volume of the solvent by means of the vibration reflecting means and that there is a minimum of power loss because of the minimum of aeration of the solvent in the ultrasonic chamber made possible by the fact that the filtering means and the cooling means are operated independently of each other and are operated intermittently as required.

Many alterations and changes may be made without departing from the spirit and scope of this invention which a is set forth in the appended claims which are to be con- Above chambers 6 and 8 is the vapor space '10, and

surrounding tank 2 and integral therewith is the cooling jacket 54 through which a' coolant, such as water, is caused to flow thereby condensing the solvent vapors. Extending around the interior of the tank 2 and at a level below the lowermost points of the cooling jacket 54 is condensate trough 56 in which are collected the condensed vapors which, as a liquid, is passed through conduit 58, into and through water separator 60, from which the water is separated and then drained through valve 62, and then back into ultrasonic chamber 8 through conduit 64.

Positioned and supported in ultrasonic chamber 8 is perforated tray 66 upon which the work piece or work pieces to be cleaned and degreased are positioned and supported. During the cleaning and degreasing operation, the solvent from ultrasonic chamber 8 is periodically filtered during the operation of the apparatus to remove accumulated foreign matter by pumping it through conduit 68, through filter means '70, through conduit 72, and thus back into chamber 8 by means of pump 74. The solvent is drained from boiling chamber 6 and/or ultrasonic chamber 8 through conduit 76 and/or conduit 78, respectively, by means of pump 80, and through drain conduit 82 which is opened or closed by means of manually operated valve 84.

To clean anddegrease workpieces 86, 86 such as gears, the said workpieces are first submerged in the boiling solvent in chamber 6 and positioned on perforated tray 50 and then removed from chamber 6 and submerged in the solvent in ultrasonic chamber 8, on tray 66, through and in which are generated ultrasonic vibrations which cause the solvent to impinge against the surfaces of the work pieces. The ultrasonic vibrations are reflected by the coil 26 and the air cushioned baflles 32 and 34 thereby directing vibrations throughout the solvent in all directions therethrough to cause the solvent to impinge strued as broadly as possible in view of the prior art.

I claim:

1. An ultrasonic degreaser for cleaning a work piece comprising, in combination, an ultrasonic chamber for containing a solvent therein, means for generating ultrasonic vibrations in said solvent positioned to be submerged in said solvent, and means for reflecting the ultrasonic vibrations through said solvent in predetermined directions, said reflecting means including a gaseous cushion positioned below the level of said solvent in said chamber, whereby the solvent is caused to impinge against a plurality of surface portions of a work piece submerged in said solvent and whereby a maximum of ultrasonic vibrations is reflected by said reflecting means.

2. An ultrasonic degreaser for cleaning a work piece comprising, in combination, an ultrasonic chamber for containing a solvent therein, means for generating ultrasonic vibrations in said solvent positioned to be submerged in said solvent, means for reflecting the ultrasonic vibrations through said solvent in predetermined directions, said reflecting means including a gaseous cushion positioned below the level of said solvent in said chamber and means for controlling the temperature of said solvent, said temperature controlling means including a coolant coil in said solvent, whereby the solvent is caused to impinge against a plurality of surfaces of a work piece submerged in said solvent and whereby a maximum of ultrasonic vibrations is reflected by said reflecting means including said coolant coil. 7

3. An ultrasonic degreaser for cleaning a work piece comprising, in combination, an ultrasonic chamber for tions, said reflecting means including a gaseous cushion positioned below the level of said solvent in said chamber and means for controlling the temperature of said solvent, said temperature controlling means including a coolant coil in said solvent, and means for intermittently filtering said solvent, said temperature controlling means and said filtering means each comprising a separate flow circuit, each of said circuits beginning and ending in said chamber, whereby the solvent is caused to impinge against a plurality of surface portions of a work piece submerged in said solvent, whereby a maximum of ultrasonic vibrations is reflected by said reflecting means including said coolant coil, and whereby the temperature of the solvent can be controlled independently of the filtering of the solvent.

4. An ultrasonic degreaser for cleaning a work piece omp sin in comb natio s, an u traso ic c ambe or ontain n so n he in, means to: g nera ing asonic vibrations in said solvent, and means for reflecting the ultrasonic vibrations through said solvent in predetermined directions, said reflecting means including a gaseous cushion positioned below the level of said solvent in said chamber, whereby the solvent is caused to impinge against a plurality of surface portions of a work piece submerged in said solvent and whereby a maximum of ultrasonic vibrations is reflected by said reflecting means.

5. An ultrasonic degreaser for cleaning a Work piece comprising, in combination, an ultrasonic chamber for containing a solvent therein, means for generating ultrasonic vibrations in said solvent positioned to be submerged in said solvent, means for reflecting the ultrasonic vibrations through said solvent in predetermined directions, said reflecting means including a gaseous cushion positioned below the level of said solvent in said chamber and means for controlling the temperature of said solvent, said temperature controlling means including a multiple pass coolant coil in said solvent, whereby a solvent is caused to impinge against a plurality of surface portions of the work piece submerged in said solvent and whereby a maximum of ultrasonic vibrations is reflected by said reflecting means including said coolant coil.

6. The ultrasonic degreaser of claim 3 wherein said coolant coil is a multiple pass coolant coil.

7. The ultrasonic degreaser of claim 5 wherein said multiple pass coolant coil is substantially vertically positioned in said solvent.

8. An ultrasonic degreaser for cleaning a work piece comprising, in combination, an ultrasonic chamber for containing a solvent therein, means for generating ultraultrasonic vibrations in said solvent, and means for reflecting the ultrasonic vibrations through said solvent in predetermined directions, said reflecting means including means for controlling the temperature of said solvent, said temperature controlling means including a coolant coil in said solvent in said chamber and a gaseous cushion positioned below the solvent level, whereby the solvent is caused to impinge against a plurality of surface portions of a work piece submerged in said solvent and whereby a maximum of ultrasonic vibrations is reflected by said coolant coil.

9. The ultrasonic degreaser of claim 8 wherein said coolant coil is a multiple pass coolant coil.

10. Ultrasonic cleaning apparatus for cleaning work pieces comprising, in combination, an ultrasonic chamber for containing a cleaning liquid, means for generating ultrasonic vibrations in said cleaning liquid, and means for reflecting the ultrasonic vibrations through said cleaning liquid in predetermined directions, said reflecting means including a gaseous cushion positioned below the level of said solvent in said chamber, whereby the cleaning liquid is caused to impinge against a plurality of surface portions of work pieces submerged in said cleaning liquid and whereby a maximum of ultrasonic vibrations is reflected by said reflecting means.

11. An ultrasonic degreaser for cleaning a work piece comprising, in combination, an ultrasonic chamber for containing a solvent therein, means for generating u1trasonic vibrations in said solvent and means for reflecting the ultrasonic vibrations through said solvent in predetermined directions, said reflecting means including a gaseous cushion fixedly positioned below the level of said solvent in said chamber.

12.. Ultrasonic cleaning apparatus for cleaning work pieces comprising, in combination, an ultrasonic chamber for containing a cleaning liquid, means for generating ultrasonic vibrations in said cleaning liquid, and means for reflecting the ultrasonic vibrations through said cleaning liquid in predetermined directions, said reflecting means including a gaseous cushion fixedly positioned below the level of said solvent in said chamber.

13. An ultrasonic degreaser for cleaning a work piece comprising an ultrasonic chamber for containing a solvent therein, means for generating ultrasonic vibrations in and through said solvent, and gaseous cushion means for reflecting ultrasonic vibrations through said solvent in predetermined directions said gaseous cushion means being below the solvent level, whereby the solvent is caused to impinge against a plurality of surface portions of a work piece in said solvent and whereby a maximum of ultrasonic vibrations is reflected by said reflecting means.

References Cited in the file of this patent UNITED STATES PATENTS 2,057,177 Wolfl Oct. 13, 1936 2,468,550 Fruth Apr. 26, 1949 2,495,295 Spanier Jan. 24, 1950 2,529,762 Brisse Nov. 14, 1950 2,771,086 Kearney Nov. 20, 1956 2,828,231 Henry Mar. 25, 1958 2,831,785 Kearney Apr. 22, 1958 2,845,077 Branson July 29, 1958 2,860,646 Zucker Nov. 18, 1958 

